Why there is so much hype on SDN regarding Ws? Why do people feel it is worth than F? This is just not true! Though I would prefer B over W, but saying that somehow W is worth than F is nonsense, at least because F will tank your GPA while W will not.
Why? Because while a W will not kill an application, it is certainly not viewed favorably, and the implication is that it to avoid something much worse than a B. That's why. You may have misunderstood, if you thought I meant taking a F is better than a W. It never would be. By the same token, a W would never be better than a B, and, in most cases, would not even be better than a C since you'd also have to retake a class that you otherwise would have passed, and one or two Cs would not do enough damage to a GPA to be worth the effort.
A W is not the end of the world, but it also is not a badge of honor. It is preferable to an F, but otherwise, if you have done the work and are going to pass the class, you are usually better off taking the C and moving on. I'm not sure why this is a discussion, though, because you too would prefer a B, so why are you questioning the advice?
Do you honestly think any adcom looks at a W and views it the same as if there were a blank space on the transcript? If that were the case, schools wouldn't report Ws at all. Ws generally indicate a problem that caused the student to withdraw, rather than a passing grade that the student wanted to improve by taking the class again. If you have an emergency and need to withdraw from a semester, adcoms would be understanding and forgiving. If you are selectively using Ws to avoid bad grades, adcoms understand that as well, and view them accordingly. And, the assumption is, they are avoiding something far worse than a B or a C.